Understanding the neurological processes of temperature regulation has been a challenge to researchers in a variety of disciplines over the past several decades. Four fundamental methods have been used to study the neural control of body temperature in rodents and other species: (1) thermal stimulation of CNS sites with stereotaxically implanted thermodes; (2) neurophysiological recordings of the firing rates of single neurons in thermal afferent and integrative pathways; (3) neuropharmacological stimulation of thermoregulatory pathways and measurement of neurohumoral substances in the CNS during thermal stimulation; (4) lesions and/or ablations of CNS sites. These and other methods, when applied to normal and febrile subjects, have led to the development of various regulatory models of temperature regulation. This chapter is an attempt to discuss the key aspects of what has become an enormous subdiscipline of thermal physiology.

Temperature sensitivity of the CNS

Since the 1930s it has been established that sites in the hypothalamus and preoptic area elicit thermoregulatory motor responses when thermally stimulated; for historical reviews, see Lomax (1979) and Schönbaum and Lomax (1990). There has been a major research effort to discern the comparative physiological aspects of the thermal sensitivity of the CNS. The preoptic area/anterior hypothalamus (POAH) and other sites in the CNS in rodents and other mammals are extremely sensitive to artificial displacements above or below the normal brain temperature of ∼37°C (Table 2.1).